Conventional pianos and keyboards are ubiquitous with a standardized linear series of white and black keys/buttons arranged from left to right in ascending order. The white keys/buttons represent the diatonic C major scale, and the black keys/buttons represent the sharps or flats. This layout allows performance of chords and scales in all twelve chromatic keys of western music. However, the piano layout has limitations and takes years of practice to master, needing different hand positions and patterns of notes for performing chords and scales in different keys.
Even before the introduction of electronic musical instruments, isomorphic grid keyboards have already been developed. These keyboards improve on the traditional piano's design, by creating symmetrical grids of buttons with rows and columns, which make chords and scales easier to play. One can memorize a few shapes, and move it around to play different chords. Isomorphic grids are also better adapted to typical hand shapes, easier placement of fingers, and for playing large intervals. However, a musician still needs to understand music theory to play different chords and scales in different keys. An “isomorphic” keyboard is a keyboard wherein (1) the keys are typically arranged as a vertical and horizontal grid of note buttons and (2) intervals between notes on the keyboard are associated to fingering having the same (or similar) shape (cf., for example, the Merriam-Webster dictionary for the definition of “isomorphic”). In this respect, prior art “isomorphic” keyboards have a fixed chromatic keyboard layout (like the one shown in FIG. 2 of the present application) and permit fingering patterns which are invariant to real transposition such that, for example, major triads in different keys (C, D, E etc.) have the same fingering pattern when the hand is moved to different places on the keyboard. However, minor triads, for example, have a different fingering pattern than major triads, and this difference cannot be compensated by moving the hand over the keyboard. Accordingly, prior art “isomorphic” chromatic keyboards still require an extensive knowledge of music theory to understand, apply and learn the different fingering patterns: The fingering pattern has to be changed, for example, for switching between a major and a minor triad.
A whole tone keyboard can be isomorphic—see, for example, the Janko keyboard which uses two rows with whole tones, set apart by a whole tone. However, it is neither diatonic nor tuning invariant—although tuning invariance requires an isomorphic layout, not every isomorphic layout is tuning invariant. The same applies to the Accordion.
U.S. Pat. Nos. 1,685,401 A, 3,417,648 A and 1,795,468 A all disclose symmetrical mechanical isomorphic keyboards, some of them intended for different tunings or temperaments. However, they are neither diatonic nor adaptive nor are they intended for the use with software. Furthermore, they use older forms of layouts.
U.S. Pat. Nos. 3,342,094 A and 3,468,209A both disclose mechanical isomorphic keyboards in a matrix shape which are arranged in 4ths. However, like the prior art mentioned above, they are neither diatonic nor adaptive nor are they intended for the use with software. Modern iOS applications such as Synthtastic, PolyPadPlayground and Mugician are similar in that they use a square isomorphic grid (and even often colors to indicate harmony). However, they are not adaptive or diatonic, either. On the other hand, ToneSpace is a software plugin which has diatonic assist, but it is still not fully dynamic.
U.S. Pat. No. 4,031,800 A and US 2008/072738 A1 disclose symmetrical mechanical isomorphic keyboards with hexagonal buttons. However, they are neither diatonic nor adaptive. There are similar hardware pieces on the market such as the Axis-64. There are also applications which follow the hexagonal layout, but they are neither diatonic nor adaptive, either—see, for example, hexaChrome, Hex OSC Full & Hex OSC S, Musix.
US 2007/022868 A1 and US 2007/022865 A1 disclose a matrix shaped backlit instrument (Tenori-On) which is adaptive—however, the usage is pertaining to rhythmic ‘step sequencing’.
U.S. Pats. Nos. 5,099,738 A, 5,502,274 A and 5,619,003 A disclose an electronic musical instrument including a keyboard which makes use of different note tables such that the user can choose therefrom when using the keyboard. This instrument is diatonic and adaptive—however, it is not isomorphic such that the gains in terms of learning chord shapes are still limited. In a similar way, the application Moog Animoog uses a dynamically adaptive diatonic piano keyboard—however, it is not isomorphic, either, with the same consequence that there are no gains in terms of learning chord shapes.
US 2011/100198 A discloses a device and method for generating a note signal upon a manual input, wherein control means generates the note signal on the one hand on the basis of the input signal and on the other hand on the basis of the allocation function. The allocation function is defined via a two-dimensional definition amount comprising a tone quality axis and a frequency axis or tone pitch information axis, and the tone qualities are represented on a first axis. The definition amount based on the coordinate system further comprises a second axis on which the tones are arranged—for this reason, the same is also referred to as tone axis or frequency axis. Accordingly, US 2011/100198 A does neither disclose an isomorphic keyboard nor a chromatic or diatonic keyboard, either, but a device with a tone generating matrix which more resembles the original Moog synthesizer.
US 2006/011044 A discloses a method of composing music on a handheld device, wherein a musical sequence is formed on the keypad of a handheld device. The numbered keys on the keypad of the handheld device are mapped to corresponding notes in an octave. The sequence of musical notes is entered by depressing at least one numbered key on the keypad and displaying a numerical representation of the sequence on the display screen of the handheld device. Accordingly, like US 2011/100198 A above, there is neither disclosure relating to an isomorphic keyboard nor a chromatic or diatonic keyboard, but merely a handheld device such as a mobile phone where musical sequences are stored.
The article “Isomorphic Controllers and Dynamic Tuning: Invariant Fingering over a Tuning Continuum” (W. Sethares et al., in: Computer Music Journal, December 2007, p. 15ff) discusses “tuning invariance” in general, and one conclusion is that it requires an isomorphic layout—however, although tuning invariance requires an isomorphic layout, not every isomorphic layout is tuning invariant.
The link “http://web.archive.org/web/20120724051804/http://robertinventor.com/ software/tunesmithy/mouse_and_pc_keyboard_music.htm” shows a software program without physical buttons but using a computer keyboard as a controller which has a diagonal layout without vertical columns. The purpose of this program is to explore a variety of non-standard tunings and to study microtonality. The computer with this program is not easy to play or finger because the scales are not implemented to wrap to different rows in a way that would make fingering of scales and chords easy. Although it can be chosen which not a button sends (which applies to any MIDI device), whole layouts cannot be changed—this could only be achieved by changing to a menu which, however, does not make a change from, e.g., D major to c minor possible without custom coding.
Thus, there is still a need for an instrument which enables its user to easily play scales or chords in any key with little musical training.